Add coffescript syntax highlighting

Imported lexer from Scintilla and added coffeescript filetype
the names in the filetype file have to match the ones in highlightingmappings, but they can be whatever you want.
In highlightingmappings the *order* is important, as it is how the keywords are set to the Scintilla lexer: by their numerical ID, which is the order there.  Normally to know what order you want you look at the Scintilla lexer's `static const char *const <name>WordLists[]`, but unfortunately this lexer has improper keyword descriptions so it's no that easy.  Anyway, it has 4 sets of keywords, and the 3rd is unsed (supposed to be used for documentation keywords inside documentation comments, but there's not documentation comments for the moment).